Sewing machine wth equipment for sewing of edge-parallel seams

ABSTRACT

The disclosure relates to a sewing machine including means for edge seaming together two or more layers of sewing material of any configuration comprising a succession of spaced, superposed supporting plates between each adjacent pair of which a separate layer of sewing material to be seamed together is passed. Means associated with the supporting plates provide a straight guiding line running at an acute angle away from the stitch forming line and means on the forming plates located in front of and laterally to the stitch forming means provide a fulcrum for pivoting the layer of sewing material passing therethrough so that the edge of each layer approaches and passes along said straight guiding line before being pulled into the stitch forming line.

llnited States Patent [191 Stockel .lan.1,1974

[ SlEWlNG MACHINE WTH EQUIPMENT FOR SEWING OF EDGE-PARALLEL SEAMS [75] lnventor: Wilhelm Stockel, Hann-Munden,

Germany [73] Assignee: lPfaff Industriemachinen GmbH,

Kaiserslautern/Pfalz, Germany [22] Filed: Sept. 21, 1972 [21] Appl. No.: 290,880

[30] Foreign Application Priority Data 1,172,430 10/1958 France 112/205 Primary Examiner-l-l. Hampton Hunter Attorney-Greene & Durr [57] ABSTRACT Oct. 1, 1971 Germany P 21 49 069.7 tween each adjacent pair of which a separate layer of sewing material to be seamed together is passed. [52] US. Cl. 112/153 Means associated with the supporting plates provide a [51] Int. Cl D051) 35/10 straight guiding line running at an acute angle away [58] Field of Search 1 12/153, 152, 150, from the stitch forming line and means on the forming 112/148, 136, 205 plates located in front of and laterally to the stitch forming means provide a fulcrum for pivoting the [56] References Cited layer of sewing material passing therethrough so that UNITED STATES PATENTS the edge of each layer approaches and passes along 2 97] 483 2H9 Cordier 112/153 X said straight guiding line before being pulled into the Stitch forming line- FORElGN PATENTS OR APPLICATIONS 519,947 4/1940 Great Britain 112/153 3 Claims, 5 Drawing Figures 1 l ar I 3\ 1 P \-I v t I E5 .1 :Hz ea I SEWING MACHINE W'llH EQUIPMENT FOR SEWING 0F EDGE-PARALLEL SEAMS The invention concerns a sewing machine with a material pusher or feeder and with a guide device, which makes it possible to produce edge-parallel seams, on work pieces, which devices includes spaced, superposed support plates in several layers.

It is known for the purpose of manufacturing edgeparallel seams on work pieces, to arrange units of straight line forming outline comprising one or more aligning rollers in front of the stitch forming place of the sewing machine. The latter impart to the sewing goods layers a corresponding straight movement as soon as the edges of the work pieces depart from that position.

With the known arrangement of this kind, one or more of the aligning rolls will control the course of the edges of the work pieces through a sensing photocell. Thus, the control impulse proceeding from the photocell changes either the angle of an aligning roll or in the presence of several aligning rolls directs the drivedetermining roll in and out.

In most arrangements of this kind, the sewing goods to be seamed together lie directly one on top of the other. Righting the drive roll will consequently align the combined workpiece. A relative movement between the individual work pieces with respect to one another and the mutual alignment of the same is otherwise not possible. One is therefore forced to lead into the machine, the layers of goods to be stitched from the beginning.

Other similar known arrangements are adpated only for the alignment of rectilinearly bordered workpieces. They are further very expensive to construct since for practically each layer of sewing goods, a separate alignment device is required, each of which comprises a photocell, an alignment roll shiftable parallel to its long axis, and an alignment roll, shifting servomotor.

This invention is based on the problem of making a sewing machine for the edge parallel or edge-like sewing together of several sewing goods layers which makes it possible, the making of edge parallel seams on workpieces with straight as well as with curved extending edges without the insertion of sensing straightening devices, or other templet-patternlike guides along the edge zone of the sewing goods layers.

This problem is solved according to the invention, by using a sewing machine with a material feeder and a guide device with several support plates spaced one above the other, which have straight edge or linear means extending laterally away from the stitch forming line at a sharp angle to the latter and which plates meet under initial stress for the formation of a fulcrum for each layer of sewing goods at a point laterally and in front of the stitch forming position.

With the help of such a guide device, such superposed layer of sewing goods can now be straightened independently of the remaining layers in a simple way and manner. Thereby the layer of sewing goods performs a rotational movement on its support until its edge comes into position against the straight edge or linear means.

The sewing goods layers to be united with one another can not only have any contour whatever, but can show edge forms which also develop contary to one another. The one layer can thus be curved concave, and the other, by way of example, convex. Even in such cases it is possible to bring the edge-different, individual layers which are disaligned in front of the stitch forming place through the feed-derived, rotation movement obtained by the guide arrangement of the invention into alignment on the straight edge means and to lead the resultant corresponding edges to the region of the stitch forming position. With the device of the invention, the layers of whatever contour can be moved along a preferably rectilinearly proceeding line and thereby be supplied straightened out to the stitch forming place.

In order to be able to straighten materials from layers of different strengths with a single apparatus, it is further proposed by the inventor to make the distance of the plates changeable. Through the changing of the distances of the plates, the pressure exerted on the individual layers can be fitted directly to the thickness and the gliding ratio of the actual layers of sewing goods.

A satisfactory fixing of the fulcrum for the layers is reached when the plates, in front of and laterally to the stitch forming place, exhibit at least one thickening means on their successive opposite sides at the located position.

In the attached drawing is shown our exemplified embodiment of the guide device made according to the in vention and explained in detail below.

FIG. l is a plan view of the region of the stitch forming place of a sewing machine with the apparatus of the invention.

FIG. 2 is a cross-sectional view taken on line II II of FIG. 1.

FIG. 3 is a partial cross-sectional view taken on line III III of FIG. 1.

FIG. 4 is an enlarged showing of a cross-section along line IV IV of FIG. 2.

FIG. 5 is a front view of a second embodiment of the apparatus.

The arm I of the sewing machine is shown in dotdash lines in FIG. 1. In the known way, the sewing machine is equipped with a looper (not shown), a cooperating thread-guiding needle 2, a lower material feeder 3, and a convention pressure foot 41.

On the base plate 5 of the sewing machine, a carrier plate 7 is fastened, which carries several pegs 7 arranged one after the other in succession, laterally of stitch forming line of the sewing machine.

The pegs 7 form a line or straight edge 8 for the edge of each sewing goods layer and are, as especially evident in FIG. I, said straight line 8 passing at a sharp angle to the feed direction of the sewing goods. Guide piece 9, mounted on carrier plate 6 is arranged after the pegs 7, the guide piece 9 being so constructed at the side surface 10 facing the stitch forming line, that the part in front of the material feeder 3 lies along a tangent to the pegs 7 and the part 12 situated laterally of the material feeder 3 extends parallel to the feed direction of the sewing goods.

On the carrier plate 6, two plates 13,14 are arranged extending essentially parallel one over the other in spaced relation, the height of the same from carrier plate 6 being adjustable by threaded bolts 15 of the carrier plate 6. To obtain this adjustment, both plates 13,14 are provided, on their right ends, as shown in FIG. I, with a strip 16 which in the area of threaded bolt have a recess 17 (FIG. 3) to provide for their up take by the collar of a positioning nut m. Through twisting of the positioning nuts 18 which rotate within the trips 16, the distance between carrier plate 9 and the lower plate 14, or between both plates 13,14 can be changed.

Both plates 13,14 are provided with borings in the area of pegs 7 which safeguards the unhindered mutual displacement of the plates in the vertical direction.

For facilitating the adjustment of mutual spacing of the plates, spacing pieces 19,20 (FIGS. 2 and 3) of predetermined thickness can be positioned between said plates. This will guarantee a quick and reliable adjustment of the reciprocal distance of plates 13,14.

Not only the carrier plate 6, but also both plates 13,14 exhibit, at position 21, in front of and laterally to the stitch forming part of the sewing machine, thickenings 22 facing each other, which as will be explained below, and which form a momentary pivot point 23 (FIG. 1) for the sewing goods layers.

The modified structure of the invention shown in FIG. has a carrier plate 30 fastened on the base plate 5 of the sewing machine, which carries a strip 31. The side surface 32 of strip 31 here serves as the line for the edges of the individual sewing goods layers and is so shaped that its part situated in front of the material feeder 3 passes laterally and at a sharp or acute angle to the stitch forming line, while that part suitated laterally of the material feeder 3 passes parallel to the feed direction of the sewing goods.

On the side surfaces 32 of strip 31, two plates 33,34 are fastened which are likewise mutually spaced, which are essentially parallel to one another, but which come into contact at a region 35 in front of and laterially to the stitch forming position thereby forming a pivoting point for the particular sewing goods layers.

The bow 36 serves for fixing the pivot points and for adjustment of pressure with which plates 33,34 weigh upon each other or on the carrier plate 30. The bow is held from two threaded pegs 38 fastened on the strip 31. Both threaded pegs 38 are surrounded by pressure springs 39 and each is provided with an adjusting nut 40 with the aid of which the attached bow 36, and consequently the reciprocal pressure bearing on plates 33,34 is adjustable.

The manufacture of an edge parallel seam is accomplished as follows:

The two layers of sewing goods 25,26 to be sewed together, and which can have any desired outline form, are guided in between the carrier plate 6 and plate 14 and between the two plates 13,14, respectively. The distance between carrier plate 6 and plate 14 and between the plates 13 and 14 respectively is so adjusted that each layer 25,26 is still guided between the plates, but at the same time is retarded due to the thickenings 22 at point 21.

To begin an operation, the sewing goods layers 25,26 will be brought edgewise under the stitch forming place of the sewing machine by the operator. The initial stitches are then sewed in the usual way. While forming the next stitches, the material feeder 3 carries out a pulling force in the feed direction on the sewing goods layers and imparts to the sewing goods layers 25,26 the usual feed movement. Through the pulling force exerted on the layers 25,26 and the retarding effect of the thickenings 22 on the plates 6,13 and 14, each layer 25 or 26 executes an instantaneous pivotal movement about the pivot point 23 (determined by the thickenings 22). Since the layers 25,26 are separated from one another through plates 13,14 and also since the retarding effect of each pair of plates is adjustable, the rotating movement of the upper layer 25 is independent of the rotating movement of the lower layer 26.

Through the rotation, the edge of each sewing goods layer will be rotated over to the line 8 formed through the pegs 7 and then moved along this line. Both layers 25,26 come thereby, independently and separately from each other, along line 8 of the device, being rectifled thereby, and in the further development of the feed movement, move edgewise to the stitch forming position. It should be noted herewith, that the retarding forces exerted on the individual layers of sewing goods, and thereby the turning moment of the feeding movement derived therefrom, should be suited in like proportions to said respective layers and not taken to such a high value as to cause bulging of the edges of the layers along the line 8.

The structure of the apparatus of the invention has been illustrated in the preceeding examples by the sewing together of two layers of sewing material. The apparatus is not limited to the sewing together or hemming of only two layers of sewing goods, rather any number of layers of sewing material may be seamed together edgewise. It is only necessary that the number of plates be suited to the number of layers, namely, the number of plates provided must be such that a proper supporting space with a corresponding pivot exists for each layer of sewing goods.

With the apparatus of the invention, it is even possible, by the use of a proper guide for each layer of sewing goods, which layers are to be sewed edge parallel to form, not only edgewise aligned, but edge parallel seams thereon by the use of plural needle machines which then the individual layers produce different spacings from the edge.

I claim:

1. In a sewing machine equipped with a carrier plate and a material feeder defining a stitch-forming line along the carrier plate of the machine, an improved device for sewing edge parallel seams on several layers of sewing goods, comprising guide means defining a straight edge-guiding line extending from the approach side of the material feeder at an acute angle to the stitch-forming line,

a series of superposed plates corresponding in number to the number of layers of sewing goods to be seamed together and extending substantially parallel to the carrier plate of the machine and laterally of the edge guiding lines,

and aligned pivot means between the carrier plate and the first superposed plate and between adjacent superposed plates, each spaced laterally and in front of said stitch forming line adapted to pivot and cause the sewing goods pulled therebetween by the material feeder to pivot so that the edges of said sewing goods pass along said edge guiding line.

2. The sewing machine as claimed in claim 1 comprising means for adjusting the spacings of said superposed plates.

3. The sewing machine as claimed in claim 1 said aligned pivot means comprise at least one thickened portion on each of the supporting plates. 

1. In a sewing machine equipped with a carrier plate and a material feeder defining a stitch-forming line along the carrier plate of the machine, an improved device for sewing edge parallel seams on several layers of sewing goods, comprising guide means defining a straight edge-guiding line extending from the approach side of the material feeder at an acute angle to the stitch-forming line, a series of superposed plates corresponding in number to the number of layers of sewing goods to be seamed together and extending substantially parallel to the carrier plate of the machine and laterally of the edge guiding lines, and aligned pivot means between the carrier plate and the first superposed plate and between adjacent superposed plates, each spaced laterally and in front of said stitch forming line adapted to pivot and cause the sewing goods pulled therebetween by the material feeder to pivot so that the edges of said sewing goods pass along said edge guiding line.
 2. The sewing machine as claimed in claim 1 comprising means for adjusting the spacings of said superposed plates.
 3. The sewing machine as claimed in claim 1 said aligned pivot means comprise at least one thickened portion on each of the supporting plates. 